Optical modulators are used to electrically modulate a laser beam from a laser source. One type of optical modulator includes a crystal and a drive circuit that applies a driving voltage across the crystal. In this design, the laser beam is directed at the crystal. The voltage across the crystal changes the index of refraction of the crystal. The amount in which the index of refraction is changed is proportional to the amount of voltage applied to it. With this design, the crystal changes the path length of the laser beam through the crystal in accordance with the frequency of the driving voltage. Thus, a laser beam emerging from the crystal is modulated by the frequency of the driving voltage.
Typically, a voltage source directs only a few volts to the driving circuit. However, the crystal requires a much higher voltage to properly modulate the beam. Accordingly, the drive circuit must direct a relatively high voltage to the crystal. Unfortunately, existing drive circuits can be relatively physically large in size, expensive, low in sensitivity, complicated, and/or inefficient to operate. Moreover, existing drive circuits may only be able to be tuned to relatively low resonant frequencies.